Strategies used to cope with psychological stress appear to play a major role in, determining stress-related outcomes such as physical and subjectiv well-being. Coping may involve approach strategies, in which attention is directed toward the source of stress and its effects on the person, or avoidant strategies, in which attention is directed away from stress. Whereas the approach/avoidance distinction is captured by a number of existing paper-and-pencil instruments, these measures suffer from a variety of conceptual and methodological problems. This project examines a novel approach for assessing approach/avoidant coping as it pertains to the individual's orientation toward negative affect associated with stress. The approach involves quantification of the degree to which the individual's self-report of emotional distress is concordant with physiologic responses to stress. It is hypothesized that effective coping is associated with concordance between these two aspects of the stress response, and that less effective coping is associated with a lack of concordance characterized either by an exaggeration (approach) or minimization (avoidance) of subjective distress relative to physiologic activity. This hypothesis is derived from a control systems framework in which negative affect is seen as feedback that guides the selection of cognitive and instrumental coping responses. This line of reasoning will be evaluated in two studies, each of which will be conducted using independent samples of 60 college students an 60 community residents. The first is a laboratory study in which variation in self-report and physiologic responses to stress will be created through administration of a battery of standard psychological stressors. The second study will be conducted in the naturalistic setting where an ambulatory blood pressure monitor will be used to measure physiologic activity and a diary to acquire self-reports of affect. It is hypothesized that (1) stress-response concordance measures will show modest associations with conceptually similar, traditional coping measures; (2) stress-response concordance measures will contribute to the prediction of physical health after controlling for traditional coping measures; (3) these effects will be stronger for within-subject as compared with between-subject assessments of stress-response concordance. This research should lay the groundwork for subsequent research in which assessments of stress-response concordance may be used to determine the effects of approach and avoidant coping styles on physical and mental health.